Automatic gate-operating mechanism



Patented Dec. 14, 1920.

E. P. SAWHILL.

6 Y We? NW 0 E0 W W APPLICATION FILED APR.14, 1917.

AUTOMATIC GATE OPERATING MECHANISM.

E. P. SAWHILL' AUTOMATIC GATE OPERATING MECHANISM.

APPLICATION FILED APR.14, 1917.

1,362,441, 7 Patented Dec. 14, 1920.

2 SHEETS-SHEET 2.

UNITED STATES PATENT QEFICE.

EDGAR P. SAWI-IILL, 0F CLEVELAND, OHIO, ASSIGNOR TO THE C. O..BARTLETTAND SNOW COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.-

AUTOMATIC GATE-OPERATING MECHANISM.

neeaaai. A

Specification of Letters Patent.

Patented Dec. lat, 1920.

To all whom it may concern.

Be it known that I, EDGAR P. SAWHILL, a citizen of the United States,and a resident of Cleveland, county of Cuyahoga, and State of Ohio, haveinvented a new and useful lmprovement in Automatic Gate-0peratingMechanism, of which the following is a specification, the principle ofthe invention being herein explained and the best mode in which I havecontemplated applying that principle, so as to distinguish it from otherinventions.

The present invention relates to hoisting mechanism and has particularreference to automatic means for controlling the filling of the hoist orbucket. The means for opening and closing the gate controlling the discharge opening have been perfected so that the filling of the bucketstops when a predetermined load is reached. These means for opening andclosing of the gate, and the means for lowering the discl'iarge aproninto position and for raising the same out of the path of the buckethave been provided and are arranged to operate in the correct order. Themain object of the invention, however, is the automatic closing of thedischarge gate when a predetermined load has been received in thebucket. To the accomplishment of the foregoing and related ends, saidinvention, then, consists of the means hereinafter fully described andparticularly pointed out in the claims.

The annexed drawing and the following description set forth in detailcertain mechanism embodying the invention, such disclosed meansconstituting, however, but one of various mechanical forms in whichtheprinciple of the invention may be used.

In said annexed drawings 1- Figure 1 is a side elevation of the device;and Fig. 2 is a front elevation of the same.

The present mechanism will be employed with a bucket hoist or likeapparatus and is particularly suitable for use in connection with ahoisting bucket which will be carried along a trolley. Inthe figuresthere is shown the usual hopper or supply chamber 1 terminating in adischarge opening 2. Guides or centering means 4 for the bucket 5 aremounted in the pit 3, and consist of upright members which are flaredoutwardly at the top, and are thus adapted to receive and center thebucket as it is lowered. In the pit bottom, on suitable base members 6,are mounted guideways or upright members 7 in which is slidably mounteda cradle 8 upon which the bucket 5 will rest. The cradle is formed withupwardly extending side portions so that it will contact with theguideways over a large area to give a smooth action and prevent jamming.As shown, the cradle is balanced by counter-weights 9 which are attachedto the cradle by means of chains 10 passing over pulleys 11 mounted inthe top of the guides.

Closing the discharge-opening in the hopper is a pivotally mounted gate12, which moves upwardly to close the opening. At

the upper end of this gate is a small apron 13 which is adapted to actas a discharge chute when the gate is opened. The gate has rearwardlyextending arms 14 on which are mounted counterweights 15 to maintain thegate in its normal closed position.

Pivotally mounted upon the framework 16 which carries the hopper is adischarge apron 17 which is normally in an inoperative position, asshown in dotted outline, but is adapted to be lowered below the smallapron on the gate to carry the material into the bucket or hoist. Thisapron is connected to the cradle by means of a link 18 and thecounterweights 9 for the cradle 8 are also adapted to take care of theweight of the apron so that the apron will be maintained in itsinoperative position until the weight of the bucket on the cradle lowersthe cradle suiiiciently to swing the apron down below the gate opening.When the bucket is hoisted the counterweights will immediately returnthe cradle 8 to its normal upward position and will thus move the apron17 out of the path of the bucket 5.

The cradle is formed with an extension 19 on the side toward the hopperand this extension is provided with an elongated slot 20, through whichis mounted a rod 21 pivotally attached at its upper end to the gate 12,and this rod is adapted to open the gate upon being moved downwardlvthrough the action cause the gate to open, thus letting the materialdischarge into the apron and the bucket.

The means for releasing the gate are mounted in the pit bottom below thecradle. Upon a suitable base 23' a lever 24k is pivotally mounted, andthis lever has a bearing roller 25 on its upper side adapted to becontacted by the cradle 5 when the gate has been opened. At the otherend this lever is attached to a link 26 which is connected to one end ofa bell crank lever 27 mounted on a small base member 28 in the pit. Theother arm of this bell crank is adapted to contact the rod below thecradle extension and a pre-determined downward movement of the cradlecauses the bell crank to force the rod outof engagement with theextension, thus letting the gate close. To normally maintain the rod 21in position to engage with the extension a small counterweighted bellcrank 30 is pivotally mounted on the extension and adapted to contactwith said rod to keep it in the engaging position.

Pivotally attached to the lever 24 is a rod 31, which is connected atits upper end to one end of a counter-weighted lever 32, pivotallymounted on a bearing 33 carried by the frame-work. This lever carries acounter-weight 34 which balances or compensates for the bucket load andthis weight is made adjustable along the rod so the load may be variedor so that different types of materials may be handled. A block 35 iscarried on the frame-work (upon which the counterweight normally rests),and a second bumper 36 is attached to the frame work and adapted tolimit the upward travel of the counterweight and arm.

The operation of the device starts with the normal inoperative positionof the gate 12 and the apron 17. As soon as the bucket 5 rests upon thecradle 8, the weight of the bucket will be suflicient to overcome thecounterweights 9 for the cradle and thus lower the same sufiiciently tobring the apron into its discharge position. The weight of the bucketwill be suflicient to force the cradle down enough further to open thegate and when this has occurred the cradle will be resting upon thebearing roller 25 in the lever arm 14. The material will then dischargeinto the bucket and the added weight of the material will be sufficientto slowly overcome the counterweight 34 connected to the lever arm 32,and as soon as this counterweight is overcome the cradle will again dropsufiiciently to operate the bell-crank lever 27 to disconnect the rod 21holding the gate open and the gate will then be automatically shut bythe action of its own counterweights 15. As soon as the operator beginshoisting the bucket the counterweights 9 for the cradle will immediatelyraise it and also bring the apron 17 up into its inoperative position,allowing the bucket a clear path of travel upwardly out of the centeringguides 4. The gate which operates upwardly to close the dischargeopening will almost instantaneously cut ofi? the discharge or" thematerial and thus the slight increase in weight of the materialdischarged which will fiow after the gate begins to close may be readilycalculated, and the material in the bucket when it is ready to behoisted will be practically an equal amount for each load. 'In this waythe amount of material handled may be readily ascertained.

It will be clear that the gate cannot be opened except when there is anempty bucket on the cradle, thus preventing an accidental discharge ofmaterial. The use of the undercut gate stops the discharge of materialso quickly that there is no material spilt into the pit or onto thecradle as has been the case in former types of automatic hoistingapparatus. Further, there is no loss of material from the bucket as itis not hoisted until the material has ceased to run down the dischargeapron, and in this way there is no danger of having the material dropbelow or back into the weighing and operating mechanism as has beenfound to be the case in former types of apparatus.

Other modes of applying the principle of my invention may be employedinstead of the one explained, change being made as regards the mechanismherein disclosed, pro vided the means stated by any of the 01- lowingclaims or the equivalent of such stated means be employed.

1 therefore particularly point out and distinctly claim as myinvention 1. In gate operating mechanism, the combination of acounter-weighted gate normally closed, a discharge apron normally ininoperative position, a movable cradle adapted to receive a bucket, saidcradle being connected to said gate and said apron and being adapted tofirst lower said apron, and then open said gate during a predeterminedrange of movement.

2. In gate operating mechanism, the combination of a counter-weightedgate n'ormally closed, a discharge apron normally in inoperativeposition, a vertically movable cradle adapted to receive a bucket, saidcradle being connected to said apron and said gate and being adapted tolower said apron, open said gate and release said gate respectivelyduring a predetermined range of downward movement.

3. In a gate operating mechanism, the combination of a counter-weightedgate normally closed, a discharge apron normally in inoperativeposition, a vertically movable cradle adapted to receive a bucket, saidcradle being connected to said apron and said gate and being adapted tolower said apron,

open said gate and release said gate respectively during a predeterminedrange of downward movement, upward movement of said cradle being adaptedto return said apron to its normal position.

l. In automatic gate operating mechanism, the combination of a gatenormally closed, a discharge apron normally in its inoperative position,a vertically movable cradle adapted to be operated by the weight of ahoisting bucket, means operatively connecting said. cradle and saidapron and adapted to lower the latter upon slight downward movement oithe former, and gate operating mechanism connecting said cradle and saidgate, and adapted to open said gate upon further downward movement ofsaid cradle.

5. In automatic gate operating mechanism, the combination of a gatenormally closed, a discharge apron normally in its inoperative position,a vertically movable cradle adapted to be operated by the weight of ahoisting bucket, means operativelyconnecting said cradle and said apronand adapted to lower the latter upon slight downward movement of theformer, gate operating mechanism connecting said cradle and said gate,and adapted to open said gate upon further downward movement of saidcradle, and releasing means operated by still further downward movementof said cradle, and adapted to disconnect said gate operating means toclose said gate.

6. In automatic gate operating mechanism, the combination of agatenormally closed, a discharge apron normally in its inoperative position,a vertically movable cradle adapted to be operated by the weight ofahoisting bucket, means operatively connecting said cradle and saidapron and adapted to lower the latter upon slight downward movement ofthe former, gate operating mechanism connecting said cradle and saidgate, and adapted to open said gate upon further downward movement ofsaid cradle, and releasing means operated by still further donmwardmovement of said cradle, and adapted to disconnect said gate operatingmeans to close said gate, said apron operating means being adapted toreturn said apron upon upward movement of said cradle.

7. In automatic gate operating mechanism, the combination of a gatenormally closed, a discharge apron normally in its inoperative position,guideways, a vertically movable counterweighted cradle mounted in saidguideways, and being adapted to be moved by the weight of a hoistingbucket, means operatively connecting said cradle and said apron andadapted to lower the latter into its discharging position upon downwardmovement of said cradle through a predetermined distance, gate operatingmechanism connecting said cradle and said gate, and adapted to open saidgate upon downward movement of said cradle through a furtherpredetermined distance, and re leasing means adapted to disconnect saidgate-operating mechanism upon a still further predetermined downwardmovement of said cradle.

S. In an automatic gate operating mechanism, the combination of acounter-weighted gate normally closing a discharge chute, a verticallymovable counter-weighted cradle, a link connected to said gate andadapted to be engaged by said cradle to open said gate during apredetermined downward movement of the cradle, and means operable by afurther downward movement of said cradle to disengage said link fromsaid cradle to allow said gate to close.

9. In an automatic gate operating mechanism, the combination of acounter-weight ed gate normally closing a discharge chute, guideways, avertically movable counterweighted cradle mounted in said guide ways andhaving a projection on one side thereof, a link connected to said gateand adapted to be engaged by such projection to open said gate upon apredetermined clownward movement of said cradle, and means fordisengaging said link from said projection upon a further predetermineddownward movement of said cradle.

10. In an automatic gate operating mechanism, the combination of acounterweighted gate normally closing a discharge chute, guideways, avertically movable counterweighted cradle mounted in said guideways andhaving an apertured projection on one side thereof, a link connected tosaid gate and being mounted in such aperture and having a lug adapted tobe contacted by said projection to open said gate upon downward movementof said cradle through a predetermined distance, and releasing mechanismadapted to disengage said link and said projection upon downwardmovement of said cradle through a further predetermined distance.

11. In a gate operating means for buckethoists and the like, thecombination of a movable counter-weighted cradle adapted to receive abucket, a counter-weighted gate normally closed, a rod connected to saidgate and adapted to be engaged by said cra" dle to open said gate upondownward movement of said cradle, and other means operable by furtherdownward movement of said cradle and adapted to release said rod toclose said gate.

Sgned by me this 12th day of April, 191

EDGAR P. SAWHILL.

